The invention relates to a mobile apparatus with which it is possible for a user to detect the existence of an object which exists in a traveling direction of itself while looking at a screen which displays information.
Mobile apparatuses such as mobile telephones and PDAs (Personal Digital Assistant) are widely used these days, and their functions are diverse. Depending on an application therefore, a use may need to operate a mobile apparatus while walking and looking at information which is displayed on a screen.
When one is concentrated on an indication shown on the screen while walking, he can not confirm what is ahead of him. Unable to confirm with his eyes the existence of an object such as other people and a bicycle while operating the mobile apparatus, he is exposed to danger that he collides with an object which exists in a traveling direction of itself, falls and gets hurt. To avoid such danger, it is necessary for him to detect the existence of an object which exists in the traveling direction of itself while walking.
The three-dimensional angle of a mobile apparatus largely changes depending upon how the mobile apparatus is held. For example, Japanese Patent Application Laid-Open Gazette No. 2000-250434 discloses portable information equipment which detects the direction of gravity acting on information displaying means which varies depending upon how the portable information equipment is held, and changes the direction in which information is displayed. Meanwhile, Japanese Patent Application Laid-Open Gazette No. 2001-272413 discloses an example of using a mobile telephone as an acceleration sensor or angular speed sensor.